ICND1 v2.0 Student Guide

Objectives Upon completing this module, you will be able to meet these objectives: Identify the components of a computer network and describe their basic characteristics Understand the m

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Welcome to Cisco Systems Learning Through the Cisco Learning Partner Program, Cisco is committed tobringing you the highest-quality training in the industry Cisco learning products are designed to advanceyour professional goals and give you the expertise that you need to build and maintain strategic networks.Cisco relies on customer feedback to guide business decisions; therefore, your valuable input will helpshape future Cisco course curricula, products, and training offerings Please complete a brief Cisco onlinecourse evaluation of your instructor and the course materials in this student kit On the final day of class,your instructor will provide you with a URL directing you to a short postcourse evaluation If there is noInternet access in the classroom, please complete the evaluation within the next 48 hours or as soon as youcan access the web

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You may be asking yourself, “What do I need to know to support my network?” The answer to this questiondepends on the size and complexity of the network Regardless of its size and complexity, the starting pointfor learning to support a network is the same This course is intended to be that starting point This coursefocuses on providing the skills and knowledge necessary to implement and operate a small- to medium-sized network

Learner Skills and Knowledge

This subtopic lists the skills and knowledge that learners must possess to benefit fully from the course

Learner Skills and Knowledge

Basic computer literacyBasic PC operating system navigation skillsBasic Internet usage skills

Basic IP addressing knowledge

© 2013 Cisco Systems, Inc.

Course Goal and Objectives

This topic describes the course goal and objectives

Course Goal

To provide students with the knowledge and skills necessary

to install, configure, and operate small- to medium-sized

networks.

© 2013 Cisco Systems, Inc.

Upon completing this course, you will be able to meet these objectives:

Describe network fundamentals and build simple LANs

Establish Internet connectivity

Manage network device security

Expand small- to medium-sized networks with WAN connectivity

Describe IPv6 basics

Establishing Internet Connectivity

Managing Network Device Security

Building a Medium- Sized Network

Introducing IPv6

PM

LUNCH Building a

Simple Network (Cont.)

Establishing Internet Connectivity (Cont.)

Managing Network Device Security (Cont.)

Building a Medium- Sized Network (Cont.)

ICND1 Superlab

© 2013 Cisco Systems, Inc.

The schedule reflects the recommended structure for this course This structure allows enough time for theinstructor to present the course information and for you to work through the lab activities The exact timing

of the subject materials and labs depends on the pace of your specific class

Your Training Curriculum

This topic presents the training curriculum for this course

Additional information is available at http://learningnetwork.cisco.com

Cisco Career Certifications

Cisco Certifications

www.cisco.com/go/certifications

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You are encouraged to join the Cisco Certification Community, a discussion forum open to anyone holding

a valid Cisco Career Certification (such as Cisco CCIE®, CCNA R&S®, CCDA®, CCNP®, CCDP®, CCNPSecurity®, and CCNP Voice®, and others) It provides a gathering place for Cisco certified professionals toshare questions, suggestions, and information about Cisco Career Certification programs and other

certification-related topics For more information, visit http://www.cisco.com/go/certifications

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Cisco Certified Network Associate Recommended Training Through Cisco Learning Partners

§ Interconnecting Cisco Networking Devices Part 1

§ Interconnecting Cisco Networking Devices Part 2

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Recommended Training Through Cisco Learning Partners

§ Interconnecting Cisco Networking Devices Part 1

Entry Technician

Professional

Associate

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CCNA Prep Center

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http://learningnetwork.cisco.com

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Cisco Icons and Symbols

Multilayer Switch Home Office

Wireless Conectivity

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Cisco Glossary of Terms

For additional information on Cisco terminology, refer to the Cisco Internetworking Terms and Acronymsglossary of terms at

http://docwiki.cisco.com/wiki/Category:Internetworking_Terms_and_Acronyms_(ITA)

Building a Simple Network

This module provides a high-level overview of basic networking components and their functions The needfor a communication module is explained, followed by an overview of the TCP/IP protocol stack CiscoIOS Software is introduced, and its basic functions and features are described Basic switch configuration isdescribed, with configuration examples so that learners can perform switch startup and initial configuration

in the associated lab LANs are introduced, as well as the Ethernet standard The operation and role ofswitches within LANs is described Finally, the module provides an overview of common switch mediaissues and lists recommended troubleshooting steps

Objectives

Upon completing this module, you will be able to meet these objectives:

Identify the components of a computer network and describe their basic characteristics

Understand the model of host-to-host communications

Describe LANs and the role of switches within LANs

Describe the features and functions of Cisco IOS Software

Install a switch and perform the initial configuration

Describe Ethernet as the network access layer of TCP/IP and describe the operation of switches

Identify and resolve common switched network issues

Upon completing this lesson, you will be able to meet these objectives:

Define a network and describe examples of networks

Identify common networking components by function

Interpret network diagrams

Describe the impact of user applications on the network

List the characteristics of a network

Compare and contrast logical and physical topologies

Main Office Branch Office

© 2013 Cisco Systems, Inc.

A network is a connected collection of devices and end systems, such as computers and servers, which cancommunicate with each other Networks carry data in many types of environments, including homes, smallbusinesses, and large enterprises Large enterprise networks may have a number of locations that need tocommunicate with each other Based on where workers are situated, these locations are as follows:

Main office: A main office is a site where everyone is connected via a network and where most

corporate information is located A main office can have hundreds or even thousands of people whodepend on network access to do their jobs A main office may use several connected networks that canspan many floors in an office building or cover a campus that contains several buildings

Remote locations: A variety of remote access locations use networks to connect to the main office or

to each other

Branch offices: In branch offices, smaller groups of people work and communicate with each

other via a network Although some corporate information may be stored at a branch office, it ismore likely that branch offices have local network resources, such as printers, but must access

information directly from the main office

Home offices: When individuals work from home, the location is called a home office

Home-office workers often require on-demand connections to the main Home-office or branch Home-offices to accessinformation or to use network resources such as file servers

Mobile users: Mobile users connect to the main office network while at the main office, at the

branch office, or traveling The location of the mobile users determines their network access

requirements

enterprise with many computers, printers, storage devices, and servers that are used to communicate andstore information from many departments over large geographic areas.

Physical Components of a Network

This topic describes the typical physical components of a network, including PCs, interconnections,

switches, and routers

Physical Components of a Network

Router

h c t i w S h

c t i w S

PC Printer Server Desktop Laptop

© 2013 Cisco Systems, Inc.

There are four major categories of physical components in a computer network:

Endpoints: Computers serve as endpoints in the network They send and receive data Printers and

servers are also endpoints in the network

Interconnections: The interconnections consist of components that provide a means for data to travel

from one point to another point in the network Interconnections include components such as these:

NICs, which translate computer data into a format that can be transmitted over the local networkNetwork media, such as cables or wireless media, which provide the means by which signals aretransmitted between networked devices

Connectors, which provide the connection points for the media

Switches: Switches are devices that provide network attachment to the end systems and provide

intelligent switching of the data within the local network

Routers: Routers interconnect networks and choose the best paths between networks.

Interpreting a Network Diagram

This topic describes the typical icons that represent the components of a network, including PCs, switches,and routers

Interpreting a Network Diagram

Gi0/1

Fa0/3

Gi0/0 192.168.1.0/24 Gi0/1

S0/0

S0/1

© 2013 Cisco Systems, Inc.

The network diagram captures network-related information The amount of information and the detaildiffers from organization to organization A series of lines and icons commonly represents the networktopology Some of the more common networking icons used in this diagram include the following:

Network, such as the

Internet, an access

network, a lab network, and

so on

Router Workgroup LAN switch Server

End-user desktop PC End-user laptop Ethernet link Serial link

Other information may be included in the network diagram if space allows For example, it is common toidentify the interface on a device in the S0/0/0 format for a serial interface, Fa0/0 for a Fast Ethernetinterface, or Gi0/1 for a Gigabit Ethernet interface It is also common to include the network address of thesegment in the 192.168.1.0/24 format In the example shown in the figure, 192.168.1.0 indicates thenetwork address, /24 indicates the subnet mask, and 1 and 2 at the device ends indicate IP addresses oninterfaces (.1 corresponds to 192.168.1.1)

Impact of User Applications on the Network

Applications can affect network performance and, conversely, network performance can affect applications.This topic describes common interactions between user applications and the network

Impact of User Applications on the Network

Real-time applications:

VoIP, video Human-to-human interaction End-to-end latency critical

Batch Applications

Interactive Applications

Real-Time Applications

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Historically, when considering the interaction between the network and applications that ran on the

network, bandwidth was the main concern Batch applications, such as FTP, TFTP, and inventory updates,were initiated by a user and then run to completion by the software, with no further direct human

interaction For batch applications, bandwidth was important but not critical, as long as the time needed forcompletion was not excessive Interactive applications, such as inventory inquiries and database updates,required more human interaction The user would request some type of information from the server and

then wait for a reply Bandwidth became more important because users became impatient with slow

responses However, because response time was more dependent on the server than on the network,

bandwidth was still not critical In most cases, QoS features could overcome bandwidth limitations by

giving interactive applications preference over batch applications

Like interactive applications, real-time applications such as VoIP and video applications involve human

interaction Because of the amount of information that is transmitted, bandwidth has become critical In

addition, because these applications are time-critical, latency (delay through the network) is critical

Variations in the amount of latency can affect the network Not only is sufficient bandwidth mandatory,

QoS is mandatory VoIP and video applications must be given the highest priority

Today, VoIP is promoted as a way for organizations to save money and is said to be as easy as installing aVoIP router into the network While the benefits of VoIP are easily realized in the home network, VoIP canresult in a disaster in a small-office network Simply installing a VoIP router in a network does not ensuresufficient bandwidth, nor does it provide a proper QoS scheme Applications that worked correctly in thepast may begin to run so slowly that they are unusable when someone is on the phone Additionally, voicequality may be poor You can overcome both of these issues, bandwidth and QoS, with good network

design

© 2013 Cisco Systems, Inc.

You can describe a network according to performance and structure:

Topology: In networks, there are physical and logical topologies The physical topology is the

arrangement of the cables, network devices, and end systems The logical topology is the path overwhich the data is transferred in a network For example, a physical topology describes how the networkdevices are actually interconnected with wires and cables A logical topology describes how the

network devices appear connected to network users

Speed: Speed is a measure of the data rate in bits per second of a given link in the network.

Cost: Cost indicates the general expense for the purchasing of network components and installation

and maintenance of the network

Security: Security indicates how protected the network is, including the information that is transmitted

over the network The subject of security is important, and techniques and practices are constantlyevolving You should consider security whenever you take actions that affect the network

Availability: Availability is a measure of the probability that the network will be available for use

when it is required For networks that are meant to be used 24 hours per day, 7 days per week, 365 daysper year, availability is calculated by dividing the time that it is actually available by the total time in ayear and then multiplying by 100 to get a percentage

For example, if a network is unavailable for 15 minutes per year because of network outages, you cancalculate its percentage availability as follows:

([Number of minutes in a year – down time] / [number of minutes in a year]) * 100 = percentageavailability

([525600 – 15] / [525600]) * 100 = 99.9971

Scalability: Scalability indicates how easily the network can accommodate more users and data

transmission requirements If you design and optimize a network for only the current requirements, itcan be very expensive and difficult to meet new needs when the network grows

Reliability: Reliability indicates the dependability of the components that make up the network, such

as the routers, switches, PCs, and servers Reliability is often measured as a probability of failure or asMTBF

These characteristics and attributes provide a means to compare various networking solutions

Physical vs Logical Topologies

This topic describes the physical and logical topologies of networks

Physical Topologies

Physical layout of the devices and cablingThree primary categories (bus, star, and mesh)

© 2013 Cisco Systems, Inc.

Each type of network has a physical and a logical topology

The physical topology of a network refers to the physical layout of the devices and cabling You mustmatch the appropriate physical topology to the type of cabling that you will install, such as twisted pair,coaxial, or fiber Understanding the type of cabling that is used is important in understanding each type ofphysical topology These are the primary categories of physical topologies:

Bus: In early bus topologies, computers and other network devices were cabled together in a line using

coaxial cable Modern bus topologies establish the bus in a hardware device and connect the hostdevices to the bus using twisted-pair wiring

Star: A central cabling device connects the computers and other network devices The physical

connection is commonly made using twisted-pair wiring

Mesh: Every network device is cabled with many others Redundant links offer reliability and

self-healing The physical connection is commonly made using fiber or twisted-pair wiring

Logical paths that the signals use to travel from one point on

the network to another

Router Router

Switch

E

F Switch

© 2013 Cisco Systems, Inc.

The logical paths that the signals (data) use to travel between points in the network define the way in whichdata accesses the network media and transmits packets across it

The physical and logical topologies of a network can be the same For example, in a network that is

physically shaped like a linear bus, the data travels along the length of the cable Therefore, the network hasboth a physical bus topology and a logical bus topology

On the other hand, a network can have physical and logical topologies that are quite different For example,data sent from PC A to a server can take a different path from the shortest path, as indicated in the figure It

is not always possible to predict how data travels in a network simply by observing its physical layout, soengineers often document logical topologies as well as physical topologies

A physical topology describes the layout for wiring the physical devices.

A logical topology describes how information flows through a network

© 2013 Cisco Systems, Inc.

Understanding the

Host-to-Host Communications Model

Overview

Host-to-host communications models were created to help define how network processes function,

including the various components of networks and the transmission of data Understanding the structure andpurpose of the most commonly used protocol stack, TCP/IP, is important for understanding how one hostcommunicates with another host This lesson introduces the OSI model and describes the TCP/IP protocolstack and its layers

Objectives

Upon completing this lesson, you will be able to meet these objectives:

Identify the requirements of a host-to-host communications model

Define the OSI reference model

Describe the functions of the TCP/IP layers

Describe the processes of encapsulation and de-encapsulation

Describe how peer-to-peer communications work

Introducing Host-to-Host Communications

Host-to-host communications require a consistent model The model addresses hardware, software, and datatransmission This topic describes the host-to-host communications model

Introducing Host-to-Host Communications

Two different types of host-to-host models:

Older model:

Proprietary Applications and combinations of software controlled by one vendor

Standards-based model:

Multivendor software Layered approach Examples: OSI, TCP/IP

© 2013 Cisco Systems, Inc.

The network devices that people are most familiar with are called end devices End devices form the

interface between the human network and the underlying communications network In the context of a

network, end devices are called hosts A host device is either the source or the destination of a message that

is transmitted over the network Communication begins with a message, or information, that must be sentfrom one device to another device The message then flows through the network and arrives at the end

device

Successful communication between hosts on a network requires the interaction of many different protocols

A protocol is a set of rules that govern communications Networking protocols describe the functions thatoccur during network communications Protocols are implemented in the software and hardware of eachhost and other devices

Original host-to-host communications models were proprietary Each vendor controlled its own applicationand embedded communications software An application that was written by one vendor would not function

on a network that was developed by another vendor In the computer industry, “proprietary” is the opposite

of “open.” Proprietary means that one company or small group of companies controls all use of the

technology Open means that use of the technology is available and is free to the public

Business drivers and technology advances led to a multivendor solution The first step is to separate

application software from communications software, which allows new communications technologies to beimplemented without requiring new applications However, it still requires a single-vendor solution for

communications software and hardware

Examples of such standards-based models are TCP/IP and OSI

OSI Reference Model

This topic describes the OSI reference model, which provides a means of describing how data is transmittedover a network The model addresses hardware, software, and data transmission

OSI Reference Model

1 2 3 4 5

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To address the problem of networks being incompatible and unable to communicate with each other, theISO researched different network schemes As a result of this research, the ISO created a model to serve as

a framework on which to build a suite of open systems protocols The vision was that this set of protocolswould be used to develop an international network that would not be dependent on proprietary systems

As a reference, the OSI model provides an extensive list of functions and services that can occur at eachlayer It also describes the interaction of each layer with the layers directly above and below it More

importantly, the OSI model facilitates an understanding of how information travels throughout a network Itprovides vendors with a set of standards that ensures compatibility and interoperability between the varioustypes of network technologies that are produced by companies around the world It is also used for data

network design, operation specifications, and troubleshooting

The OSI reference model separates network functions into seven categories This separation of networkingfunctions is called layering The OSI reference model has seven numbered layers, each one illustrating aparticular network function

The physical layer (Layer 1): The physical layer defines the electrical, mechanical, procedural, and

functional specifications for activating, maintaining, and deactivating the physical link for bit

transmission between end devices Physical layer specifications are defining characteristics such as

voltage levels, timing of voltage changes, physical data rates, maximum transmission distances,

physical connectors, and other similar attributes

The data link layer (Layer 2): The data link layer defines how data is formatted for transmission and

how access to physical media is controlled This layer also typically includes error detection and

correction to ensure reliable delivery of the data

The network layer (Layer 3): The network layer provides connectivity and path selection between

two host systems that may be located on geographically separated networks The growth of the Internethas increased the number of users that access information from sites around the world The networklayer is the layer that manages the connectivity of these users by providing logical addressing

The transport layer (Layer 4): The transport layer defines services to segment, transfer, and

reassemble the data for individual communications between the end devices For example, businessusers in large corporations often transfer large files from field locations to a corporate site Reliabledelivery of the files is important, so the transport layer breaks down large files into smaller segmentsthat are less likely to incur transmission problems

The session layer (Layer 5): The session layer establishes, manages, and terminates sessions between

two communicating hosts The session layer also synchronizes dialog between the presentation layers

of the two hosts and manages their data exchange For example, web servers have many users, so thereare many communication processes open at a given time It is important, then, to keep track of whichuser communicates on which path In addition to session regulation, the session layer offers provisionsfor efficient data transfer, CoS, and exception reporting of session layer, presentation layer, and

application layer problems

The presentation layer (Layer 6): The presentation layer ensures that the information that is sent at

the application layer of one system is readable by the application layer of another system For example,

a PC program communicates with another computer One PC is using EBCDIC and the other PC isusing ASCII to represent the same characters If necessary, the presentation layer translates amongmultiple data formats by using a common format

The application layer (Layer 7): The application layer is the OSI layer that is closest to the user This

layer provides network services to the applications of the user, such as email, file transfer, and terminalemulation The application layer differs from the other layers in that it does not provide services to anyother OSI layer It provides services only to applications outside the OSI model The application layerestablishes the availability of intended communication partners, and it synchronizes and establishesagreement on procedures for error recovery and control of data integrity

TCP/IP Protocol Suite

Although OSI reference model layer names are often used, the OSI protocol stack is not the most

commonly used reference model The TCP/IP protocol suite, which was defined at approximately the sametime as the OSI reference model, has become the most commonly used reference Within the set of variousindividual communication protocols in the TCP/IP protocol suite, the two most important protocols are TCPand IP

TCP/IP Protocol Suite

TCP/IP Stack OSI Reference Model

7 6

1 2 3 4 5

© 2013 Cisco Systems, Inc.

A TCP/IP protocol suite is the most popular protocol stack used in networks It specifies end-to-end

connectivity, describing how data should be formatted, addressed, routed, and transmitted Functions areorganized into the following four layers:

Link layer: The link layer covers the same processes as the two lower OSI layers, the data link and

physical layers The link layer describes the physical characteristics of a link, how access is controlled,and how data is formatted for transmission

Internet layer: The internet layer provides routing of data from the source to the destination by

defining the packet and the addressing schemes, moving data between the link layer and transport

layers, routing packets of data to remote hosts, and performing fragmentation and reassembly of datapackets

Transport layer: The transport layer is the core of the TCP/IP architecture It provides communication

services directly to the application processes that are running on network hosts

Application layer: The application layer provides applications for file transfer, network

troubleshooting, and Internet activities It also supports network APIs, which allow programs that havebeen created for a particular operating system to access the network

Note Although this course refers to the TCP/IP stack, it has become common in the industry to shorten this

term to "IP stack."